Method of producing a non-slip patterned sports ball

ABSTRACT

A method of producing a non-slip patterned sports ball includes the steps of: (a) thermal-pressing a transparent sheet and a covering sheet together within a mold having an embossing surface so that anti-slip protrusions are formed by the embossing surface on a surface of the transparent sheet opposite to the covering sheet and so that the transparent sheet is adhered to the covering sheet; (b) tailoring each of the transparent sheet and the covering sheet; and (c) sewing the covering sheet around a ball bladder, thereby covering the ball bladder.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a sports ball, more particularly to a method of producing a non-slip patterned sports ball.

2. Description of the Related Art

Conventional inflatable balls are generally made from a material, such as leather, polyvinyl chloride (PVC), or polyurethane (PU). Some conventional inflatable balls are provided with patterned designs printed on outer surfaces thereof. The patterned designs of such conventional inflatable balls, however, easily fade, peel off, or discolor after a short period of use.

A typical method of producing a conventional inflatable ball is described below.

In the first step, a back side of a thin film that is about 0.1 mm in thickness is printed with a design through a printing roller. The thin film is made of thermoplastic polyurethane (TPU).

In the second step, glue is heated and is coated on the printed back side of the thin film, and the printed back side of the thin film is adhered to a covering sheet that is made of ethylene-vinyl acetate copolymer (EVA) and that is used to cover a ball bladder.

In the third step, the covering sheet together with the thin film is cut and is then sewn around the ball bladder.

The conventional inflatable ball produced from the aforementioned method has the following drawbacks:

1. The printing roller for printing the design on the back side of the thin film must be specially made which is costly and ultimately results in the high cost of production of the conventional inflatable ball. Further, the high cost of the printing roller makes it impractical to manufacture the inflatable balls in a small batch of a particular design.

2. The outer surface of the conventional inflatable ball has no anti-slip surface, so that only minimal frictional forces are generated between the conventional inflatable ball and an athlete's hand.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a method of producing a non-slip patterned sports ball that is capable of overcoming the aforementioned drawbacks of the prior art.

According to this invention, a method of producing a non-slip patterned sports ball comprises the steps of: (a) thermal-pressing a transparent sheet and a covering sheet together within a mold having an embossing surface so that anti-slip protrusions are formed by the embossing surface on a surface of the transparent sheet opposite to the covering sheet and so that the transparent sheet is adhered to the covering sheet; (b) tailoring each of the transparent sheet and the covering sheet; and (c) sewing the covering sheet around a ball bladder, thereby covering the ball bladder.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which:

FIG. 1 is a flow chart illustrating the steps involved in a method of producing a non-slip patterned sports ball according to the first preferred embodiment of the present invention;

FIG. 2 is a schematic view of the steps involved in the method of producing the sports ball according to the first preferred embodiment of the present invention;

FIG. 3 is a perspective view of a portion of the sports ball of the present invention;

FIG. 4 is a flow chart illustrating the steps involved in a method of producing a non-slip patterned sports ball according to the second preferred embodiment of the present invention;

FIG. 5 is a schematic view of the steps involved in the method of producing the sports ball according to the second preferred embodiment of the present invention;

FIG. 6 is a flow chart illustrating the steps involved in a method of producing a non-slip patterned sport ball according to the third preferred embodiment of the present invention;

FIG. 7 is a schematic view of the steps involved in the method of producing the sports ball according to the third preferred embodiment of the present invention;

FIG. 8 is a flow chart illustrating the steps involved in a method of producing a non-slip patterned sports ball according to the fourth preferred embodiment of the present invention; and

FIG. 9 is a schematic view of the steps involved in the method of producing the sports ball according to the fourth preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described in greater detail, it should be noted that same reference numerals have been used to denote like elements throughout the specification.

FIGS. 1 and 2 illustrate the steps involved in a method of producing a non-slip patterned sports ball according to the first preferred embodiment of the present invention. These steps will be described in greater detail below, in combination with FIG. 3.

In step (A), pellets 41 are heated and formed into a thermoplastic substrate 4 having a thickness of about 1 mm. The substrate 4 is made of a material selected from the group consisting of thermoplastic rubber (TPR), thermoplastic elastomer (TPE), and polyvinyl chloride (PVC). Preferably, the substrate 4 is made of TPR or TPE.

In step (B), the substrate 4 is sent to a calendering device 91 so that the substrate 4 is formed into a thermoplastic transparent sheet 5 having a thickness less than that of the substrate 4. The calendering device 91 has a plurality of rollers 911 that press the substrate 4 therebetween. The thickness of the transparent sheet 5 ranges between 0.3 and 0.6 mm.

In step (C), the transparent sheet 5 is placed onto a surface 61 of a covering sheet 6 that has a pattern on one side thereof. The covering sheet 6 is made of cloth. The cloth may be a woven or non-woven fiber cloth. The transparent sheet 5 and the covering sheet 6 together are placed within a flat mold 92, which has two flat mold parts 921, 922. The flat mold part 921 has an embossing surface. The covering sheet 6 and the transparent sheet 5 together are thermal-pressed between the flat mold parts 921, 922. During thermal pressing, the thermoplastic material of the transparent sheet 5 is softened and is forced to penetrate the fiber texture of the covering sheet 6, thereby adhering the transparent sheet 5 to the covering sheet 6 without using an adhesive. As such, the transparent sheet 5 has an adhering surface 51 penetrating the patterned surface 61 of the covering sheet 6, and an anti-slip surface 52 opposite to the patterned surface 61. The anti-slip surface 52 is formed with anti-slip protrusions 53 (see FIG. 3) through the embossing surface of the flat mold part 921.

In step (D), the transparent sheet 5 and the covering sheet 6 together are tailored and are sewn around a ball bladder 7, thereby covering the ball bladder 7.

From the aforementioned description, the advantages of the sports ball produced using the method according to the first preferred embodiment of the present invention can be summarized as follows:

1. The patterned surface 61 of the covering sheet 6 is protected by the transparent sheet 5, so that after the sports ball of the present invention is used for a period of time, only the anti-slip surface 52 of the transparent sheet 5 will wear away while the patterned surface 61 remains unaffected. As such, the fading, peeling off, and discoloration problems encountered in the conventional sports ball are resolved.

2. The covering sheet 6 is made of cloth, which can be easily printed and which does not require printing of a single design in large batches. Hence, high printing flexibility is provided, and the printing price is low, thereby lowering the cost of production to a minimum.

3. The anti-slip surface 52 of the transparent sheet 5 allows for large friction to be generated with an athlete's hand, so that the sports ball of the present invention may be easily gripped.

Referring to FIGS. 4 and 5, in combination with FIG. 3, a method of producing a non-slip patterned sports ball according to the second preferred embodiment of the present invention is shown to be similar to the first preferred embodiment. The difference between the first and second preferred embodiments resides in the sequence of the processing steps. In this embodiment, after the substrate 4 is calendered (step B) and is formed into the transparent sheet 5, step (D) is executed, i.e., the covering sheet 6 and the transparent sheet 5 together are tailored, but only the covering sheet 6 is sewn around the ball bladder 7. The tailored transparent sheet 5 is coated with an adhesive, and is then adhered to the patterned surface 61 of the covering sheet 6.

Step (C) is executed after step (D). In step (C), the covering sheet 5, which is sewn around the ball bladder 7, and the transparent sheet 5, which is adhered to the covering sheet 5, are placed within a ball-shaped mold 93, which has an inner side provided with the embossing surface, and are thermal-pressed. A release sheet (not shown) is adhered to the inner side of the ball-shaped mold 93. The pressure inside the ball bladder 7 is increased so that the transparent sheet 5 is pressed against the inner side of the ball-shaped mold 93 and so that the anti-slip protrusions 53 are formed on the anti-slip surface 52 of the transparent sheet 5. The release sheet is removed after the ball-shaped mold 93 is opened. The advantages of the first preferred embodiment are similarly achieved using the second preferred embodiment.

Referring to FIGS. 6 and 7, in combination with FIG. 3, a method of producing a non-slip patterned sports ball according to the third preferred embodiment of the present invention is shown to be similar to the second preferred embodiment. However, in step (D) of this embodiment, after the covering sheet 6 and the transparent sheet 5 together are tailored, the covering sheet 6 is sewn around the ball bladder 7, whereas the transparent sheet 5 is temporarily adhered to the inner side of the ball-shaped mold 93 instead of being attached to the covering sheet 6. The covering sheet 6 and the ball bladder 7 are placed in the ball-shaped mold 93, and the pressure inside the ball bladder 7 is increased so that the patterned surface 61 of the covering sheet 6 contacts the transparent sheet 5. To carry out step (C), the ball-shaped mold 93 is subjected to a high frequency or ultrasonic heating, and the pressure inside the ball bladder 7 is further increased. As such, the anti-slip protrusions 53 are formed on the anti-slip surface 52 of the transparent sheet 5. The advantages of the first preferred embodiment are similarly achieved using the third preferred embodiment.

Referring to FIGS. 8 and 9, in combination with FIG. 3, a method of producing a non-slip patterned sports ball according to the fourth preferred embodiment of the present invention is shown to be similar to the first preferred embodiment. The difference between the first and fourth preferred embodiments resides in that the transparent sheet 5 is injection-molded and that steps (A) and (B) are not included in this embodiment. In particular, for thermal-pressing, the covering sheet 6 is first placed between the flat mold parts 921, 922 of the flat mold 92 with the patterned surface 61 thereof facing the flat mold part 921. Then, the transparent sheet 5 is injection-molded over the covering sheet 6 within the flat mold 92. The transparent sheet 5 is therefore adhered to the patterned surface 61 of the covering sheet 6, and the anti-slip protrusions 53 are formed by the flat mold part 921. In step (D), the covering sheet 6 and the transparent sheet 5 are tailored together and are sewn around the ball bladder 7 after thermal-pressing. The advantages of the first preferred embodiment are similarly achieved using the fourth preferred embodiment.

While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements. 

1. A method of producing a non-slip patterned sports ball, comprising: (a) thermal-pressing a transparent sheet and a covering sheet together within a mold having an embossing surface so that anti-slip protrusions are formed by the embossing surface on a surface of the transparent sheet opposite to the covering sheet and so that the transparent sheet is adhered to the covering sheet; (b) tailoring each of the transparent sheet and the covering sheet; and (c) sewing the covering sheet around a ball bladder, thereby covering the ball bladder.
 2. The method of claim 1, wherein the transparent sheet is made of a material selected from the group consisting of thermoplastic rubber (TPR), thermoplastic elastomer (TPE), and polyvinyl chloride (PVC).
 3. The method of claim 1, wherein the covering sheet is made of cloth, and has a patterned surface covered by the transparent sheet.
 4. The method of claim 3, wherein: the mold has two flat mold parts one of which has the embossing surface; the transparent sheet and the covering sheet are thermal-pressed together between the flat mold parts before being tailored; no adhesive is used between the transparent sheet and the covering sheet during thermal-pressing; and the transparent sheet and the covering sheet are tailored together after thermal-pressing.
 5. The method of claim 4, further comprising a calendering process to form the transparent sheet, wherein the transparent sheet has a thickness ranging between 0.3 and 0.6 mm.
 6. The method of claim 4, further comprising an injection-molding process to mold the transparent sheet directly over the covering sheet within the mold and to thermal-press the transparent sheet and the covering sheet.
 7. The method of claim 3, wherein: the covering sheet, after being tailored, is sewn around the ball bladder; the mold is a ball-shaped mold having an inner side provided with the embossing surface; the covering sheet sewn around the ball bladder and the transparent sheet which is tailored are placed within the ball-shaped mold during thermal-pressing; and the pressure inside the ball bladder is increased during thermal-pressing so that the anti-slip protrusions are formed on the transparent sheet and the transparent sheet is adhered to the covering sheet.
 8. The method of claim 7, further comprising attaching the transparent sheet which has been tailored to the covering sheet which is sewn around the ball bladder before thermal pressing.
 9. The method of claim 7, further comprising attaching temporarily the transparent sheet which has been tailored to the inner side of the ball-shaped mold before the covering sheet and the ball bladder are placed in the ball-shaped mold. 